The present invention relates to a process for measurement of the relative positions of the center-lines of an aperture and of a cylindrical outline of a sample, in particular a ferrule (or collet) for an optical fiber connector and which in particular enables measurement to be made of the coaxiality and/or the concentricity of said center-lines.
Ferrules for optical fiber connectors have an external outline of nominal diameter 2500 microns (+ or -1 micron) and an aperture which is coaxial to the external outline and which presents a general nominal diameter of 125 microns. The performances of optical fiber connectors depend in particular on the precision with which the aperture is positioned relative to the reference cylindrical outline. Given the tolerances mentioned above and the level of performance required for such connectors, the requirements of accuracy for the measurement of concentricity and/or of coaxiality are themselves high since the readings of the positions of the center-lines must be performed with an accuracy better than a micron.